Hard copy devices, such as inkjet printers, typically include a kicker to prevent multiple sheet picks, that is the picking of print media sheets underlying the top sheet in a stack of sheets. The kicker is conventionally used to kick the underlying sheets back into the stack.
In conventional systems, a kicker is spring biased in a kicking position before a pick. During a pick, the kicker is retracted by a kicker cam mounted on a pick roller. The kicker is kept retracted by contact with the top sheet as it advances through the printing zone. Once contact with the top sheet is lost, the kicker is spring biased back to the kicking position to kick any underlying sheets back into the stack.
The conventional kicker is disadvantageous because it is in contact with the media sheet during printing. This can cause print defects on the media such as scratch marks. The biasing force of the kicker creates drag on the media that can cause media misalignment problems such as skewing. If there are no following or underlying media sheets, the kicker will strike structures in the media path, such as a media-stopping feature, causing undesirable noise. The conventional kicker also performs a kicking motion for each pick sequence regardless of whether there is a multiple pick. Finally, the amount of kicking motion cannot be varied because the conventional kicker has a fixed length.
A need therefore exists for an active kicker system capable of selectively preventing multiple picks.